Comprehensive ex vivo and in vivo preclinical evaluation of novel chemo enzymatic decellularized peripheral nerve allografts

Abstract

As a reliable alternative to autografts, decellularized peripheral nerve allografts (DPNAs) should mimic the complex microstructure of native nerves and be immunogenically compatible. Nevertheless, there is a current lack of decellularization methods able to remove peripheral nerve cells without significantly altering the nerve extracellular matrix (ECM). The aims of this study are firstly to characterize ex vivo, in a histological, biochemical, biomechanical and ultrastructural way, three novel chemical-enzymatic decellularization protocols (P1, P2 and P3) in rat sciatic nerves and compared with the Sondell classic decellularization method and then, to select the most promising DPNAs to be tested in vivo. All the DPNAs generated present an efficient removal of the cellular material and myelin, while preserving the laminin and collagen network of the ECM (except P3) and were free from any significant alterations in the biomechanical parameters and biocompatibility properties. Then, P1 and P2 were selected to evaluate their regenerative effectivity and were compared with Sondell and autograft techniques in an in vivo model of sciatic defect with a 10-mm gap, after 15 weeks of follow-up. All study groups showed a partial motor and sensory recovery that were in correlation with the histological, histomorphometrical and ultrastructural analyses of nerve regeneration, being P2 the protocol showing the most similar results to the autograft control group.

Comparison of Printable Biomaterials for Use in Neural Tissue Engineering: An In Vitro Characterization and In Vivo Biocompatibility Assessment

“…Thus, it was possible to evaluate their ability to withstand stretch deriving from the formation of external fibrotic tissue, and if they are easy-to manipulate for clinicians [15,57]. Previous studies [37,58,59] have indicated that the Young's modulus of rat sciatic nerves varies between 10.19 and 18.66 MPa, which coincides with the Young's modulus values of FF scaffolds. The PLA and PCL scaffolds showed significant stiffness, which could potentially affect the nerve tissue structure and neuronal networks; however, this it could be addressed by blending these polymers with softer biomaterials to achieve more suitable viscoelastic properties [60].…”

Exploring an innovative decellularization protocol for porcine nerve grafts: a translational approach to peripheral nerve repair

“…Studies involve assessing the regenerative potential of various decellularization protocols on animal models to understand their effectiveness in nerve regeneration. This research is crucial for advancing the treatment of severe nerve injuries where traditional methods may not be sufficient ( Garcia-Garcia et al, 2023 ). Decellularized nerve grafts should provide a suitable substrate for nerve regeneration in which the conservation of ECM components plays a crucial role for peripheral nerve regeneration and axonal guidance ( Hsu et al, 2023 ; Mahdian et al, 2023 ).…”

Mechanisms underlying the cell-matrixed nerve grafts repairing peripheral nerve defects

“…Although dECM derived from tissues have biochemical and physical factors that support the growth of cells and tissues [ 32 ], the consistent provision of quality donor tissue constitutes a prominent constraint. Recognized challenges linked to tissue-derived dECM comprise pathogen transmission, uncontrolled degradation, and high manufacturing costs [ [33] , [34] , [35] ]. Nevertheless, the cell-based dECM with more advantages can be used to engineer scaffolds with different three-dimensional shapes and structures and other additional features to produce biomimetic tissue structures, and can be customized by selecting specific cells from a particular tissue or individual to overcome the limitations of homo- or xenotransplantation.…”